Technical characterization of the necklace of El Carambolo hoard (Camas, Seville, Spain)

Abstract

Since its accidental discovery in 1958, El Carambolo hoard (Camas, Seville) has been considered the most emblematic of all the hoards belonging to the Orientalizing period of the Guadalquivir River valley in Spain. It is an example of the economic heyday and the interrelations between native and oriental population during the 7th–6th centuries BCE. This impressive group consists of 21 artifacts. The archaeological and scientific studies carried out so far divide the pieces of the hoard into three groups depending on style, composition of the alloy and manufacture technique. Some studies have already dealt with the analysis and interpretation of Group 1, consisting of two bracelets, a series of 8 rectangular plaques and a pendant while Group 2 involves another series of 8 plaques and a pendant. Group 3 consists solely of a necklace with pendants in the form of signatory seals. The stylistic characteristics, along with the symbology of the seals, cover this necklace with mystery about its provenance.Thanks to previous studies on ancient joining methods and production techniques on several archaeological gold jewels (Group 1 of the El Carambolo hoard among others), it was possible to distinguish the different types of welding procedures and to reconstruct the manufacture steps used for a metallic object. In this work, we applied this type of study to interpret the micro-XRF results of the necklace of El Carambolo hoard.For the analysis of the hoard, a portable micro-XRF experimental set-up was specifically implemented.The bulk composition of the alloys, the welding/soldering zones and the decorations of the jewels were characterized. The results allowed identifying three joining methods, brazing, fusion welding and autogenous welding. Other joining methods, such as copper salt diffusion bonding, have not been clearly detected. The composition of the necklace is characterized by a lower gold content and higher silver and copper contents with respect to the other jewels of El Carambolo hoard. Furthermore, the necklace presents a more random use of different alloys as compared to Group 1. The results support the hypothesis of a different origin than the rest of the hoard, manufactured locally by foreigner goldsmiths from the Oriental Mediterranean Sea.